Formation lights are mounted on the exterior of an aircraft to enhance the aircraft's visibility to other aircraft flying in close proximity. For example, many types of military aircraft utilize formation lights to provide aircraft recognition and spatial orientation during formation flight activities.
Existing aircraft formation lights employ electroluminescent lamp (EL) technology, usually in the form of an electroluminescent strip. However, such conventional formation lights suffer from disadvantages relating to degradation that occurs over time. Generally, the luminescence decreases rapidly, usually decreasing by a factor of 2 within only a few hundred hours of operation. Accordingly, formation lights utilizing EL technology quickly become hard to recognize by other pilots. This results in a potentially dangerous situation when aircraft are flying in close proximity during low visibility conditions, such as nighttime.
The shape and size of formation lights must conform to various requirements. Among these constraints is that the formation lights must be relatively thin. Generally, the thickness of the formation lights used on the exterior of aircraft is less than a ½ inch (1.27 cm).
Thus, it would be advantageous to provide a formation light that exhibits less degradation over time, while maintaining the same package thickness and light uniformity as existing EL technology. Furthermore, a diode light source formation light may be much brighter than traditional EL technology.